In (CTIS) systems, the inflation pressure of one or more vehicle tires is characteristically controlled from a remote location (usually the vehicle cab) using an onboard source of pressurized fluid which is commonly compressed air from the vehicle air brake compressor and/or a compressed air reservoir.
In order to transfer the air between the axle and the tire, a variety of wheel-end valve assemblies have been developed such as disclosed in U.S. Pat. Nos.: 2,634,781; 2,989,999; 3,276,502; 4,434,833; 4,437,504; 4,640,331; 4,678,017; and 4,724,879, the disclosures of which are incorporated herein by reference.
Such prior art assemblies, although purportedly effective in transferring fluid (air) between an axle and a tire, are characteristically expensive and complex in design and have not heretofor addressed the problem of providing a rotary assembly for transferring air conveyed through a stationary axle to a rotary tire that is inexpensive and simple in design and that is adapted to provide a liquid lubricant, such as oil, for lessening friction between the rotary assembly and stationary axle.